Question

Nitric acid is generated by the action of sulfuric acid

onsodium nitrate. Nitrous acid is prepared by the action
ofhydrochloric acid on sodium nitrate. Why is nitrous acid
preparedin situ then obtained from the reagent itself.

Answer 1

Nitrous acid is prepared in situ because it is very unstable and decomposes quickly at room temperature. It is generated as needed due to its inability to be stored, contrasting with nitric acid, which is stable and can be prepared for storage and use in various industrial applications.

Step-by-step explanation:

The student has asked why nitrous acid is prepared in situ rather than obtained from the reagent itself. Nitrous acid is produced by reacting sodium nitrite with hydrochloric acid. The reason for its in situ preparation is due to its instability; nitrous acid is very unstable and decomposes rapidly at room temperature into nitric acid and nitric oxide. Therefore, it cannot be stored and must be generated as needed in the chemical reactions.

To prepare nitric acid, in contrast, sulfuric acid is reacted with sodium nitrate. Nitric acid is a strong acid and a powerful oxidizing agent, extensively used in industry for creating explosives, dyes, and fertilizers.

Nitrous acid is a weak acid and a unique oxidizing agent that reacts with strong reducing agents. Due to its propensity to disproportionation, creating it directly from sodium nitrite and hydrochloric acid is necessary to preserve its reactivity for immediate use in chemical reactions.

Answer 2

Step-by-step explanation:

Nitrous acid is prepared in situ from hydrochloric acid and sodium nitrate because it is a weak acid and unstable. It only exists in an aqueous solution.

`H^++NO_(2)^(-)\rightarrow HONO`

Nitrous acid is an unstable acid which gets decompose into the water , nitrogen dioxide and nitrogen monoxide gas.

`2 HNO_2 \rightarrow NO_2 + NO + H_2O`

Whereas nitric acid is highly stable acid which can be easily prepared from its reagent and it can easily be stored for future use.